Lichanura trivirgata or Charina trivirgata
Although the taxonomy of rosy boas is still up for debate with regards to which genus is most appropriate, the epithet trivirgata has understandably remained the same. Trivirgata refers to the three longitudinal dorsal stripes that are characteristic of this species. Since recent studies suggest that Lichanura is probably the most appropriate, for the sake of simplicity, we will use that nomenclature here (this should in no way be construed as our opinion as we are not taxonomists and therefore shall not contribute to the subject). There are currently 5 recognized subspecies of rosy boa: the Arizona Rosy Boa, L. t. arizonae; the Desert Rosy Boa, L. t. gracia; the Coastal Rosy Boa, L. t. roseofusca; the Baja Rosy Boa, L. t.saslowi; and the Mexican Rosy Boa, L. t. trivirgata. As mentioned above, each of these subspecies has the requisite three longitudinal stripes. These stripes vary in color but are usually black, brown, tan, rust or orange. The background color of rosy boas is cream, pale-yellow, tan or grey. In general appearance they are stout, powerful, shiny (or rosy!) animals. Rosy boas are relatively small constrictors; adults are usually 2-3 feet (60-90 centimeters) in length. They can live up to 20 years.
Rosy boas are native to southwestern North America, ranging from California and Arizona south to the Mexican states of Baja California and Sonora. They inhabit barren and desert landscapes, absent only from the most arid of conditions. Although they are primarily nocturnal and spend much of their time hidden in crevices, among rock piles or within rodent burrows, in the spring they are often active during the day. Activity levels are more dependent upon moisture than temperature. When it is exceedingly dry rosy boas stay below ground to retain moisture.
Rosy boas adapt readily to captivity and do not require a lot of space. A 20-gallon aquarium is large enough for an adult snake. Enclosures should be horizontally oriented, but still provide for some vertical climbing as rosy boas occasionally like to climb. Rosy boas are desert dwellers and do not like high levels of humidity. Caging should provide adequate ventilation to prevent the buildup of moisture. Aquariums with a screen top work well. They also like to burrow and should be provided with 2-3 inches (5-8 centimeters) of a substrate suitable for this behavior. Pine shavings, aspen bedding, sand, alfalfa pellets or another similar substrate should be used. Avoid aromatic wood chips like cedar or walnut as they can be toxic in confined quarters. Regardless of the type of substrate used it should be kept meticulously dry. They should be provided with a basking area of 90-95 degrees Fahrenheit, with a drop of 10-15 degrees on the opposite side. Since much of the rosy boa’s natural thermoregulation is done by burrowing (to escape the heat, cold or aridity) this is most efficiently provided by an undertank heating element such as heating tape, wire or pads. Since rosy boas are crepuscular or nocturnal UV Lights are optional, but many keepers are better able to enjoy their snake’s natural coloration with artificial lighting, and UV lighting certainly doesn’t hurt. Provided adequate substrate for burrowing, hide boxes are usually not necessary. Branches, logs and rocks can be provided for climbing and hiding, but make sure they are anchored so they do not accidentally crush the snake if they burrow below them. In the wild, rosy boas come across water infrequently at best. Water should be offered sparingly (once a week at most) and the bowl should not be left in the enclosure for more than a day at a time. The water bowl should be shallow enough that the snake cannot completely immerse itself.
Rosy boas, like all boas, are constrictors. Naturally they feed mainly on rodents and other small mammals, but have also been known to eat birds and lizards. In captivity their diet consists predominantly of various sized mice and they adapt very easily to frozen/thawed rodents. Ideally, prey items should be 1 to 1 ½ the diameter of the thickest part of the snake’s body. Young snakes should be offered food twice a week, with adult snakes being fed once a week or ten days.
Occasionally a neonate rosy boa will have a particular affinity for lizards and will eat nothing else. Frequently this can be overcome by gradually switching to rodents that have been scented with a lizard (this can be as simple as rubbing a lizard over the rodent’s fur).
Occasionally rosy boas exhibit a reluctance to eat. Frequently this is the result of some aspect of husbandry. If your snake won’t eat, do not handle it, check that the temperatures are warm enough, provide it with a hide box, and try offering smaller (or different) prey items.